if you read pearl of pandaria you find out that pandaria and the turtle are two of the most important things the naga have been looking for since the sundering, the mighty soldiers it created, its magical brews, its powerful artifacts that were known about during the night elf empire and everything else on pandaria was KEY to them conquering the planet.
so.... theres naga out in the ocean looking for pandaria 24/7 and... not a single one shows up? not even a small scouting party? an entire continent is discovered and they have nothing to say about it?
just doesnt add up.